1. Field of the Invention
The present invention relates in general to the production of lime slurry and the transportable reaction/mixing apparatus used to manufacture the slurry. Specifically, the present invention relates to a single-entity apparatus for mixing solid lime and water to form a lime slurry that can be operated and transported by one person to a remote jobsite.
2. Description of the Prior Art
Calcium based compounds such as CaO and Ca(OH)2 have many practical uses. For instance, these substances are used in treating waste water and sewage, soil neutralizing agents and nutrients, ground stabilization for construction, and components for building materials.
Calcium oxide (CaO) is often referred to as quicklime, while Ca(OH)2 is referred to as hydrated lime-both being referred to as xe2x80x9climexe2x80x9d. Quicklime is usually in the form of lumps or pebbles. Dry hydrated lime is usually a powder. In order to further process these compounds and improve the ease with which they are handled, dry CaO or Ca(OH)2 is usually mixed with water to form a slurry. In the case of quicklime, the water reacts with the quicklime in an exothermic reaction to form hydrated lime. This is often referred to as slaking. During the slaking of quicklime, large amounts of heat are generated which can significantly raise the temperature of the slurry.
Lime slurries can be made in batches or in a continuous process. If a particular user requires a large amount of lime slurry at a particular site, large capacity slaking and storage tanks can be permanently located on the site. These tanks can usually provide a sufficient supply of lime and lime slurry for most operations. Often, however, it is not practical to provide permanent slaking or storage tanks for forming lime slurries. In the agricultural industry and in some construction industries, lime may be required only periodically or during certain seasons. Here, the limited use of lime may not justify the investment required for construction and maintaining large capacity processing tanks and equipment. In other industries the location of the jobsites may change from day to day, such as in road construction, so that permanently located processing and storage tanks would be impractical. Here, lime slurries would have to be made at permanent lime processing facilities and then pumped into tanks to be hauled to the specific job locations.
Portable equipment for forming lime slurries which can be moved from site to site, are described by Teague et al. (U.S. Pat. No. 4,329,090) and Shields et al. (U.S. Pat. No. 5,507,572). These devices have several drawbacks, however. The major drawback to these devices is that they are large and cumbersome, requiring several pieces of equipment that need to be hauled separately, thus requiring more manpower and expense to operate. In the Shields et al. device, there is no capacity of delivering the slurry made in the tank to tank trucks for spreading the hot lime slurry to a road surface. To achieve that function, it was necessary to have an additional piece of equipment that could take the hot lime slurry from the device and pump it to the delivery truck using a separate, additional piece of equipment. This equipment had to be brought to the remote jobsite by a separate truck and thus required additional expense, power source, and manpower. This limits the commercial applicability of the devices to larger sites and larger projects. Small projects and sites where space is limited, which are often the case, are thus impractical for use for the transportable lime slurry devices to date.
Some lime consumers do not purchase quicklime and slake it for their own consumption. Indeed, most cannot justify the cost of capital slaking equipment and the problems attendant to another processing step that slaking entails. Their lime requirements are simply too small. Consequently in order to make slaked lime more economical, an improved method of slaking and the apparatus used for slaking is highly desirable.
What is needed is an easily transportable device that can expand the practical commercial use of lime slurries at remote sites. This would require an apparatus that can be operated by one man and being self-contained such that all the power sources and equipment necessary for the slurry operation are on one unit. This invention is directed towards such an apparatus and method of producing lime slurries.
The present invention is a single-entity lime slurry reactor for production and delivery of lime slurry to remote jobsites. The reactor is an apparatus comprising a unitary frame substantially parallel to the ground and having a horizontal axis. A tank body is attached to the frame, the tank body having a horizontal axis parallel to the horizontal axis of the frame, a generally cylindrical exterior, and an interior surface, the interior surface forming a mixing chamber. Power units are attached to the device in order to make it self-contained. A power unit, typically a diesel powered engine, is coupled to the frame for powering hydraulic units such as a mixer, suction pump, and delivery pump. A transport means is used to transport the apparatus to a jobsite such as a tractor, the apparatus being pulled from a forward platform and trailer hitch arrangement, or other means. In order to make the apparatus both appropriate for the highway and a mixing apparatus at a jobsite, a vertical placement means is provided. The vertical placement means is used for placing the frame, tank body, and power unit in a working position once at a jobsite and a raised position when pulling the apparatus on a highway, the working position being such that the frame is against the ground and supporting the tank body and the raised position being such that the frame and tank body clear the ground surface sufficiently to travel on a highway.
At least two inlets attached to both sides of the tank body are provided. The inlets are arranged such that solid lime can be introduced below the surface of a slurry formed within the mixing chamber. There is also a rotatable and retractable delivery outlet which is rotatable to one side of the apparatus for slurry delivery, and can extend above a truck or other carrier located alongside the apparatus.
The tank body forms a mixing chamber therein, where a mixing device such as an auger is located. The auger is powered by a hydraulic unit located on either the forward platform, or a rear platform. Other power units are also located on the rear platform. Also, wheels may be located on the rear platform for facilitating the towing of the apparatus behind a vehicle.
Additional objects, features and advantages will be apparent in the written description which follows.